The invention relates to a control device intended to be associated with a booster, especially with a booster equipping the braking system of a motor vehicle.
More specifically, the invention relates to a control device intended to be used on a booster, such as that described in U.S. Pat. No. 4,117,769. This patent describes a booster comprising, in the usual way, a housing in which is seated a drive piston forming inside the housing a front chamber and a rear chamber. The actuation of the brake pedal moves an input control member of the booster which acts on a control valve, the effect of which is to generate a pressure difference between the rear chamber and the front chamber. This pressure difference results in the application of a boosting force which is added to the mechanical force exerted on the control member.
In this document, the booster also possesses, inside the rear chamber, an auxiliary drive member having a pressure chamber capable of being connected to an external pressure source by means of a control device. When the control device is actuated, the auxiliary drive member thus exerts on the drive piston of the booster an auxiliary boosting force completely independent of the boosting force caused by the actuation of the brake pedal. In U.S. Pat. No. 4,117,769, this auxiliary boosting force is used completely independently of the normal braking system of the vehicle, in order to make it possible to add an assisted automatic braking system to the latter, without the need to resort to an additional booster.